Surgical procedures for the repair of a torn or detached retina are known. Such procedures include laser surgery, cryotherapy, scleral buckling, pneumatic retinopexy and vitreous surgery with air, gas, or silicone oil. In addition, gas has been used to repair macular holes. For eye surgery involving the use of a gas bubble, (i.e. retina detachment repair or macular hole repair) the patient must maintain a face down position for approximately four weeks post-operatively.
Many devices have been proposed to assist the patient during this four week period. One such device, sold by Palex Inventions, Inc., is shown in FIGS. 1 and 2. FIG. 1 shows a side view of the device. In dotted lines in FIG. 1 is the head up position of the head attachment portion of the device; specifically, the adjustable head strap, 1A, and the foam covered support, 6A. The head strap, 1 or 1A, is shown extended, as if fastened about the back of the head while the forehead rests against foam covered support, 6 or 6A. The adjustable jaw slide, at 2, adjusts the device into a head up or head down position. To put on the device, the head attachment portion is placed in the head up position, the foam covered bars, 7, disposed across the shoulders, and thereafter, the support belt, 3, fastened about the waist, and the head strap fastened about the back of the head while the forehead rests against support 6.
FIG. 2. is a front view of the device in the head down configuration, illustrating the foam covered support bar, 8, extending across the back of the apparatus, and adjustable height extensions 4. The device is made of aluminum tubing and foam padding, with a nylon support belt 3. An optional mirror, 5 in FIG. 1, may be mounted on an arm extending below the face of the wearer, and is said to provide safety while walking. While the Palex device claims to provide support to the head, neck, and back of the wearer, it is a cumbersome device, which provides no real viewing ability, leaving the wearer cut off from his or her surroundings. While the one mirror, 5, may provide an upside down view of objects in front of the wearer, it creates, at best, a crude, and potentially disorienting, navigational device.
A simple head support device, without a forward viewer, is described in an of advertisement by Oakworks in Ophthalmic Surgery and Lasers, July 1996. It comprises a horizontal, foam covered, inverted U-shaped head support, receiving the sides and top of the head, for comfortably maintaining the patient in a head down position. The support is mounted on a pole which rises from the front of the seat of what appears to be an ergonomic chair. U.S. Pat. No. 5,177,823 describes a similar Oakworks device in combination with a patient examining chair, or more complex chair construction. While these devices provide support for the head while the patient is seated in the device, they lack a portable forward viewer, limiting the activities of, and discouraging mobility in, the post-operative patient.
A headrest apparatus, with viewer, for use by patients convalescing from surgery to reattach a detached retina is shown in U.S. Pat. No. 5,408,713 to Stratton, et. al. The Stratton et al. headrest provides a table or a double mirror forward viewer, on a vertical support column. While the apparatus may be pulled up to a table, it leaves the patient at a distance from the table. The table top device of the present invention may be placed on top of the table in front of the patient It makes it easy for the patient to come directly up an existing table, such as their own dining or work table. When used on a table top, the device provides a comfortable headrest. Using the device of Stratton, the patient must constantly maneuver his feet about its forty centimeter base. In addition, the height of the Stratton apparatus limits its portability, realistically eliminates its ambulatory use, and renders it difficult to transport about the home, much less outside, to a restaurant or the home of friends or relatives. The table top device of the present invention yields many advantages over the floor based device of Stratton.
Numerous viewing devices have been provided to permit the supine viewer to view an object near his feet, e.g. a television, or medical service provider; see U.S. Pat. Nos. 3,019,689, 4,650,299, and 5,061,055. In addition, "glasses-type" devices with prisms rather than lenses, for viewing toward the feet, have been commercially available for a number of years. Another prism device, a camera lucida, used for drawing and copying, patented in 1807 by William Hyde Wollaston, utilizes a carefully placed prism to recreate the forward image on a drawing surface. Prisms in higher powers needed for forward viewing generally distort, making them inappropriate for use in general viewing devices, which are used for a moving or rotational view and for viewing objects at various distances. In fact, attempts to use prisms to "look around" produces a slightly delayed, but definite, nausea in the user.
There are a number of horizontal viewers for the bicyclists who ride in a face down position. Some are double mirror viewers. U.S. Pat. No. 4,375,316 to La Vantine describes a double mirror device which is rotatably attached to the crossbar of the handlebar. The viewing angles are shown in FIG. 1. FIG. 7 illustrates the adjustment of the bottom (eyepiece) mirror, followed by the adjustment of the top (objective) mirror by pulling back on its top edge and rotating the entire device about the crossbar. U.S. Pat. No. 5,148,327 to Gaxiola, referring specifically to La Vantine, describes what is believed to be better viewer, mounted at the centerline of the bicycle, forward of the handlebars, by attaching it to the center support post or goose neck of the bicycle. U.S. Pat. No. 5,305,153 to Kochocki utilizes spherical, bowl and ball mirrors to create viewing devices with curved reflecting surfaces to broaden the field of view. In addition, the device shown in FIGS. 4-7 uses multiple reflecting and viewing surfaces to produce greater height, as well as breadth, of view.
An alternative viewing apparatus worn on the face of the bicyclist (i.e. glasses or goggles) is shown in U.S. Pat. No. 4,679,916 to Roller et. al. Roller et. al. identifies the disadvantages of the two mirror bicycle mounted devices, as follows: 1) vibrations in the bicycle frame produce distortions in the image, 2) there is no side view, only a view directly ahead, which doesn't accommodate turning, and 3) it is too awkward and time consuming to constantly realign the mirrors while the rider alternates between sitting on the seat or standing on the pedals.
Another goggle or glasses type viewer is shown in U.S. Pat. No. 5,422,759 to Lee. The Lee apparatus is intended to be worn with the head erect. This device uses two mirrors or reflecting surfaces to produce a horizontally split image with the view downward presented in a mirror below the horizontal line of sight of the wearer. A similar device, shown in U.S. Pat. No. 5,173,720 to Lee et. al., allows the wearer to read a book in his lap without having to bend his neck. In contrast, the viewing devices of the present invention permit the user to view forward while encouraging a head down position.
Another viewing device is seen in U.S. Pat. No. 4,759,621 to Hawkins. This device permits the viewer to see the information shown on a computer screen, in a mirror at the level of a desk. The device is said to be useful for those who use bifocals, to eliminate the need to look up to a computer screen, and down to the desk. In fact, the device would be difficult for such a user, as the focal distance of the reflected view of the computer screen would not be the distance to the desktop, but a distance equal to the optical path to the viewing mirror, up to the object mirror, and across to the computer screen. Thus, the focal distance for the mirror view would be greater than the distance to the desktop, or the distance to the computer screen.